ALBERT

Notes: Increased activity in the fields of ground-water geology and hydrology has focused attention on the academic preparations required of a geologist or engineer planning to enter the field of ground water. In an effort to improve understanding of the educational facilities available in the United States and Canada, the Research Committee of the Technical Division of the National Water Well Association is periodically inquiring into the status of these facilities.To arrive at a better understanding of the formal course work in ground water, a seven-item questionnaire was circulated to appropriate educational institutions in May 1960. A report, “Educational and Academic Research Facilities in Ground-Water Geology and Hydrology in the United States and Canada”, was published in May 1961 summarizing the information obtained from returned questionnaires. A similar survey was made in May 1963 to obtain data on advancements in educational facilities in ground water since 1960.This report, a contribution of the Technical Division of NWWA, is based on questionnaires completed in 1963 and provides statistical data on university and college facilities in the field of ground water. Detailed information is presented on 1) course work, 2) textbooks, 3) degrees granted, 4) descriptions of departments offering course work, 5) course instructors and 6) student training and employment. Recent advancements in educational facilities are summarized. It is hoped that the statistical and descriptive information embodied in this report will provide a suitable background for those who wish to assess the adequacy of available educational facilities in ground-water geology and hydrology.

Notes: This paper describes the new percussion-reverse circulation system, designed and developed in Italy for water-well drilling. In a special reverse circulation rig, the percussion bit, consisting of a tube with external welded blades, slides up and down on the outside of the hollow drill pipes, while the hollow drill pipes remain still. The field of application of the reverse circulation method is thus enormously enlarged; either hard, cemented formations or soft, unconsolidated deposits, as well as big boulders of any size are bored much faster and more efficiently than with any other method of drilling, provided that a sufficient source of water is available.

Notes: My subject does not deal directly with either wells or ground water - it does report to you the present (October, 1963) status of construction of one of the world's greatest projects in water resource development. What is the California State Water Project? What areas will it serve? What progress is being made? The answers are the story told in this paper.The magnitude of the project is measured in terms of quantity of water, money and time. The amount of water is four million acre-feet, estimated to meet the needs of the deficient areas it will serve until at least 1990. The cost is $1,750,000,000. The time is nine years from now to begin the delivery of water to the southernmost communities on the State's system.

Notes: Predictions of where and how a fluid waste may travel from disposal site to the water table require detailed information on the physical characteristics, location, and extent of all pervious and impervious materials in the unsaturated zone. Principles concerning the flow system in the unsaturated zone indicate the importance of choice of disposal technique in predicting the time required for the fluid waste to traverse the distance to the water table. With appropriate data on the location, extent, and physical properties of water-bearing materials and on the boundaries of the saturated zone flow system, it is possible to analyze the relative merits of a variety of waste disposal techniques and to describe the probable consequences of each. Environments of consolidated rocks, such as granites, sandstones, and limestones, pose problems in addition to those related to unconsolidated or granular porous media in defining the fluid-flow regimes that involve joint patterns, fracture patterns, solutional openings, and the rock structure.The consequences of ground-water contamination can be just as damaging to water users as the pollution of surface streams. In fact it can be argued that the consequences are far more damaging because they persist over much longer periods of time after the contaminating source has been eliminated. It would appear prudent, therefore, to guard against contamination of the ground-water resource in the first instance, rather than to engage in long expensive rehabilitation measures after the damage has been done.In 1960 Graham Walton presented data concerning contamination, by sewage or other man-made wastes, of surface and underground waters. The circumstances attending the reported incidents of contamination, especially those involving ground-water supplies, have aided materially in the choice of a few principles and ideas that will identify the role of some significant hydrologic factors in the underground movement of fluid wastes.Walton's discussion of ground-water contamination refers often to physical settings into which fluid wastes are discharged at or near the land surface into cesspools, tile-drain fields, and holding ponds. Furthermore, most reported instances of ground-water contamination have taken place in relatively humid

Notes: Future water-level declines in deep sandstone wells penetrating the Cambrian-Ordovician Aquifer, the most highly developed aquifer for large ground-water supplies in the Chicago region, are considered. The Cambrian-Ordovician Aquifer is encountered at an average depth of about 500 feet below the land surface at Chicago; it has an average thickness of 1000 feet and is composed chiefly of sandstones and dolomites. Recharge is received from overlying glacial deposits in areas averaging 47 miles west of Chicago and from leakage through a shale confining bed.Geohydrologic conditions are simulated by a model aquifer, i. e., a semi-infinite rectilinear strip of sandstones and dolomites 84 miles wide and 1000 feet thick. The model aquifer is bounded by a recharge boundary 47 miles west of Chicago and by two intersecting barrier boundaries 37 miles east and 60 miles south of Chicago, and is overlain by a confining bed consisting mostly of shale averaging 200 feet thick. The hydraulic properties of the model aquifer and its confining bed, the image-well theory, and appropriate ground-water formulas are used to construct a mathematical model which provides a means of evaluating the practical sustained yield of the aquifer and predicting future water-level declines. Records of past pumpage and water levels establish the validity of this mechanism as a model of the response of the aquifer to heavy pumping.Pumpage from deep sandstone wells concentrated in six pumping centers has increased from 200,000 gallons per day (gpd) in 1864 to 96.5 millions of gallons per day (mgd) in 1961. As a result of heavy pumping, water levels in deep sandstone wells declined more than 650 feet at Chicago between 1864 and 1961.The maximum amount of water that can be continually withdrawn from existing pumping centers without creating critical water levels or exceeding recharge is estimated to be about 46 mgd. Withdrawals from the Cambrian-Ordovician Aquifer have exceeded the practical sustained yield since 1959. It is estimated that about 65 mgd could be obtained by shifting one existing pumping center toward the west and by adding 2 new pumping centers north and northwest of Chicago.Unless lake water is made available to those areas with short supply a pumpage increase from 96.5 mgd in 1961 to 243 mgd in 2010 can be expected. Using this pumpage increase and taking into consideration dewatering of portions of upper units of the aquifer, declines in nonpumping water levels that may be expected between 1963 and 2010 at existing pumping centers were computed by using the mathematical model.Pumping water levels in most pumping centers will be at critical stages a few feet above the top of the lowermost and most productive unit of the aquifer by 2010.

Notes: Much underground gas storage depends on the presence of ground water for its effectiveness. Many of the techniques of the geohydrologist are useful in exploration, design, and development of underground storage fields for natural gas. Both local and regional geologic and hydrologic conditions are pertinent to gas storage effectiveness. Behavior of water in aquifers and their caprock zones can be used to predict behavior with gas. Leakage has been common in underground gas storage.Conflict between the public interest in gas storage and water resource development as both are expanded in the future is to be anticipated. There are many problems yet remaining in the development of underground gas storage to insure the complete effectiveness of design and operation.

Notes: Hydrogeologic studies in foothill watersheds have included diamond-core drilling, installation of observation wells, and pumping tests. Detailed study of recovered cores has provided reasonable estimates of porosity. Pumping tests of the two-inch diameter wells have given estimates of the transmissibilities ranging from 6 to 600 gallons per day per foot. Test data from several wells indicate that the hydraulics of water movement in jointed rock systems is not governed by the usual mathematical models.

Notes: It is of the utmost importance that ground-water users understand the basic concept that all the ground water within a single set of hydrologic and geologic boundaries is part of a single hydrologic system. It is therefore worthwhile for all ground-water users to understand the manner in which ground water moves through the pore spaces of saturated rock and to understand the various configurations of the water table brought about by the pumping of water table wells. The movement of ground water is illustrated in two hydraulic models which were constructed in order to bring ground-water flow into surroundings where it can be visually observed. The models consist of watertight plexi-glass cases containing a porous consolidated mixture of sand and epoxy resin, which simulates a true sandstone. The models are used to study cones of depression produced by pumping wells. Photographic histories of several ground-water flow conditions are illustrated.

Notes: The hydrology of ground-water recharge depends upon the physical and chemical characteristics of both soil and water. These characteristics must be measured and related to subsurface storage space and water movements to determine the feasibility of a site for recharge and to select appropriate methods and systems of recharge. Then water may be efficiently stored underground to be used independently or conjunctively with releases from surface storage reservoirs.

Notes: Flow-distribution curves, constructed from velocity graphs of current-meter traverses, can be used to locate water-bearing and nonwater-bearing zones in an aquifer or in separate aquifers in a well and to determine the quantity of water entering between various depths. Current-meter traverses in artesian wells in northeastern Florida show the applicability of flow-distribution curves.The velocities recorded in the uncased portion of a well by a deep-well current meter reflect either changes in the cross-sectional area of the bore at the different depths or movement of different quantities of water through the well at these depths. Reasonably accurate measurements of the flow at certain depths in the uncased portion of a well can be determined by constructing flow distribution curves. These curves are constructed by utilizing points of maximum velocity, which are assumed to be levels having the minimum diameter of the well.Artesian wells in northeast Florida are generally cased to the top of the Floridan aquifer through 500 to 600 feet of clay, marl, and dolomite of Miocene to Recent age. The wells are completed open hole in the Floridan aquifer to depths of from 650 to 1,400 feet. Current-meter traverses were run in four wells in the vicinity of Jacksonville.Flow-distribution curves constructed from the velocity graphs indicate three separate water-bearing zones occur in the aquifer. The first water-bearing zone lies from about 600 to 800 feet below the land surface; the second, from 900 to 1,200 feet; and the third lies below 1,280 feet. These water-bearing zones are separated by relatively impermeable non-water-bearing zones. Bar graphs constructed from the flow-distribution curves show that the first water-bearing zone yields from less than 10 to as much as 35 percent of the water; the second water-bearing zone yields more than 50 percent of the water; and the third water-bearing zone yields about 20 percent of the water with a penetration of only 50 to 70 feet. The flow-distribution curves from current-meter traverses made while there was no surface flow indicate internal leakage of less than 70 gallons per minute in wells 2 and 4 while the wells were not discharging at the surface. Leakage probably does not occur between these zones while the wells are discharging.

Notes: The writer reviews some of the best known features of mechanical dispersion and the influence of molecular diffusion on breakthrough curves obtained for saturated and nonsaturated samples of porous medium. Miscible flow is also considered as flow of a non-homogeneous fluid in a porous medium. Special concepts of head, as introduced by Lusczynski, are reviewed and modified in order to facilitate the determination of the velocity field in the zone of dispersion. The method described is applicable in principle to the migration of water in building materials exposed to sea water.

Notes: The Savannah area obtains most of its water supply from the principal artesian aquifer. The aquifer consists of limestones of middle and late Eocene age. Unflushed salty water is present in the lower water-yielding zones of the aquifer in the eastern part of the area and sea water is entering the upper water-yielding zones in the northeastern part of the area. The salty water in the lower zones and the upper zones is moving slowly toward Savannah because a cone of depression created by pumping has reversed the natural hydraulic gradient.

Notes: Eighty-one state agencies are engaged in hydrologic investigations. Many of these agencies have vigorous programs involving many phases of water resources; a few merely administer state funds in state-federal cooperative programs. The scopes of activities differ from state to state and include observation-well measurement, stream gaging, areal investigation, site investigation, statewide compilation, drilling test wells, cooperation with the U. S. Geological Survey, providing geologic support for hydrologic investigations, basic research, studying special problems, and publication of hydrologic reports.

Notes: Alluvial aquifers underlying Cigli Air Base near Izmir, Turkey are moderarely permeable (Pf= 1,600 gallons per day per square foot) but contain brackish waters. To circumvent the need for construction of an expensive electro-dialysis treatment plant, an area several miles to the north was explored for water of good quality to meet the base requirement of 600 gallons per minute.Forty-eight vertical resistivity soundings were made along six traverses. Profiles thus obtained delineated an area favorable for testing. Test drilling at or near three recommended locations resulted in three supply wells completed in an 11 to 23 foot thick gravelly sand 260 or more feet deep.The aquifer is artesian and tests indicated a field coefficient of permeability (Pf) in the range 5,000 to 8,500 gallons per day per square foot with declines to the south. Step-drawdown test data suggested that the design capacity of the three wells, from north to south, be 800, 500, and 400 gallons per minute, respectively.Water sampled during pumping tests is chemically good, with a maximum 490 parts per million total solids and a maximum 50 parts per million chlorides. The danger of salt-water encroachment is present, however, and well waters are being sampled routinely so that encroachment may be detected early and consequent remedial action taken.

Notes: The Hele-Shaw viscous flow model has been found to be a useful device in analyzing and studying certain types of ground-water flow problems. The discussion includes the theory of the Hele-Shaw model, scaling considerations, construction techniques, and examples of problems adaptable to this model such as recharge pits, seepage of saline water, tidal fluctuations and others.

Notes: Electric analog computers are playing an important role in the forecast of consequences of developing nonhomogeneous aquifers in Illinois having highly irregular shapes and boundaries and a wide variety of head and discharge controls. Analog computers are versatile and simple equipment, of low to moderate cost, with which ground-water development schemes can be rapidly and accurately tested and the relative merits of alternate choices of development can be appraised.The electric analog computer used by the Illinois State Water Survey consists of an analog model and excitation-response apparatus, i.e., waveform generator, pulse generator and oscilloscope. Analog models are regular arrays of resistors and capacitors and are scaled-down versions of aquifers and confining beds where present. Resistors are inversely proportional to the coefficients of transmissibility and vertical permeability aquifers and the coefficients of leakage of confining beds. Capacitors store electrostatic energy in a manner analogous to the storage of water in the aquifer. The behavior of the electrical network is described by an equation which has the same form as the finite-difference equation for nonsteady state two or three-dimensional flow of ground water. Electrical units (voltage, coulombs, amperes and seconds) and corresponding hydraulic units (feet, gallons, gallons per day and days) are connected by 4 scale factors.Excitation-response equipment force electrical energy in the proper time phase into the analog model and measure energy levels within the energy-dissipative resistor-capacitor network. Oscilloscope traces, i.e., time-voltage graphs, are analogous to time-drawdown or time-recovery graphs and describe drawdown or recovery conditions after a step function-type change in discharge. A catalog of time-voltage graphs provides data for construction of a series of water-level change maps. Close agreement of water-level declines determined with an analog computer and analytical methods for 3 selected idealized aquifer situations is noted with satisfaction.An electric analog model for the East St. Louis area was assembled. The sand and gravel aquifer in the East St. Louis area has an average thickness of 120 feet, an average width of 7 miles and an average length of 30 miles. The analog model for the aquifer consists of a regular array of 2800 resistors and 1350 capacitors. The scale of the model is 1 inch equals 2000 feet. Values of resistors range in magnitude from 2.2 megohms to 33,000 ohms; capacitors are 2500 micromicrofarads. The effects of the Mississippi River were simulated by terminating the portion of the electrical network along the river in an open circuit. Resistors large in magnitude were connected to terminals along the edge of the aquifer and to ground to simulate small amounts of sub-surface flow through bluffs. The accuracy and reliability of the electric analog computer was established by comparing past records of water-level declines and values of water-level declines determined with the analog computer. The electric analog computer was used to evaluate the practical sustained yields of existing pumping centers, to predict the effects of a selected scheme of development and to deter-mine the potential yield of the aquifer under assumed pump-ing conditions.An electric analog model for the Champaign-Urbana area was assembled. The sand and gravel aquifers in the Champaign-Urbana area are contained in the Mahomet buried bedrock valley which extends across the central part of Illinois from the Indiana border to the Illinois River Valley. The Mahomet buried bedrock valley averages about 12 miles wide in the Champaign-Urbana area and is largely filled with glacial drift ranging in thickness from 50 to 440 feet. Sand and gravel are encountered within the glac-ial drift at depths between 60 and 120 feet (upper aquifer), 140 and 170 feet (middle aquifer) and below a depth of 200 feet (lower aquifer). The upper aquifer is thin and discontinuous; the middle aquifer has an average thickness of 43 feet; and the lower aquifer often exceeds 100 feet thick. Till averaging 120 feet thick (upper confining bed) overlies the middle aquifer; about 30 feet of till (lower confining bed) separates the middle and lower aquifers. The analog model for the complex aquifer system consists of a regular array of 7500 resistors and capacitors. The scale of the model is 1 inch equals 1 mile. Values of resistors range from 1 to 68,000 ohms; values of capacitors range from 10e6 to lo-' farads. The analog model consists of 2 horizontal arrays of resis-tors and capacitors (lower and middle aquifers) and 1 hori-zontal ground wire array (water table) interconnected by two vertical arrays of resistors (lower and upper confining beds). The accuracy and reliability of the electric analog computer are being assessed. The computer will be used to predict the effects of future ground-water development and the practical sustained yields of existing pumping centers in the Champaign-Urbana area.

Notes: Transmissibility (T) may be estimated from the results of routine pumping tests of water wells when only discharge (Q), drawdown (s) and aquifer thickness (m) are known:

Notes: The following is a listing of abstracts of papers presented at recent meetings or appearing in other publications which are of interest to those in the field of ground water.Abstracts of papers presented during the 1963 National Water Well Exposition - San Francisco, California, September 29-October 3, 1963 (as published in the Water Well Journal, Vol. 17, No. 9).Analysis of Current Meter Data by Flow-Distribution Curves, Leve, Gilbert W., Geologist, U. S. Geological Survey, Jacksonville, Florida

Notes: This paper describes an electric log and what it can do for water well contractors and ground-water hydrologists. Electric logs furnish data on depth of hole, where casing should be set and perforated, static water levels, relative water-yielding properties of aquifers, water quality, character of formations encountered, etc. The electric log is a permanent record of a water well which can assist in planning future repair work.

Notes: In 1957, the High Plains Research Foundation, Plainview, Texas, initiated a full scale program to investigate all factors affecting the recharge of surface water to the ground-water formation. Some of the factors being investigated and studied are: rate of recharge, effects of solids contained in the lake water being recharged, maintenance practices, and evaluation of different filtering materials. This program was started because of concern about the declining water table and the potential of the lakes as a means of recharging the formation.Artificial ground-water recharge in the High Plains is accomplished by injecting water collected in playa lakes into a well constructed for this purpose. Either by gravity or pumping, water is placed back into the underground formation through the well casing in reverse of the pumping process. These wells can be used for irrigation crops as regular irrigation wells.

Notes: The determination of aquifer transmissibility by the bail-test method can be considerably simplified if proper attention is paid to the regular spacing of bailer cycles. The transmissibility calculation will then depend on the evaluation of the difference between two numbers, instead of on the evaluation and summation of a large set of numbers, one number for each bailer cycle. The mathematical development on which this method is based is given briefly and a table listing the sums of the reciprocals of the natural numbers, which is used in the simplified determination, is also presented.The formula for the recovery of the water level after repeated bailing of a well completed in a confined aquifer (Skibitzke, 1958) may be written (Ferris et al., 1962):

Notes: The modern water well contractor is a combination structural engineer, mechanic, geologist and sanitarian. Contractor's skills and accumulated knowledge should be assembled within an area and used as the basis for design and water well specifications. Engineering a water well should have the primary objective of obtaining an adequate supply of potable water, with equal importance placed upon the protection of the source of supply.The drilling of a test bore should be included in the design of every water well. A properly drilled and accurately logged test bore can determine exact design features and equipment requirements. In an area where formation samples may be deceiving and where a more accurate log is required, it is possible to contract for an electric log of the test bore. When it is essential to obtain truly representative samples in an uncontaminated form, core samples may be taken as the test bore is being drilled.Well drillers have the right in most places to procure water for the consumers in the quantities available, and along with this right, they have the obligation of preventing contamination or depletion of the source of supply. It is the well drilling contractor's position to either directly design his projects or consult with the designing agent, making recommendations that will enhance quality rather than convenience or economy.The water well driller should acquaint his customer with modern construction procedures and modern water well design just as he has become aware of building codes and architectural specifications in the construction of buildings and homes. Contractors must keep pace with the achievements of technical people associated with the water well industry by self-education and incentive. The water well industry should be, and is, proud of its responsibility.The design and construction of a water well is no longer limited to the procurement of underground water, but also entails certain obligations on the part of the designer or contractor. Every industry, particularly those who produce consumer goods, have certain responsibilities, but none of their products are as absolutely essential to the existance of life or have a more important role in the social and economic welfare of mankind than the product of the water well drilling industry.No other group has more knowledge of the vast underground water resources or the importance of the

Notes: “Hidden recharge” is defined as subsurface percolation of water from basin-margin mountains directly into aquifers of the valley basins. It is an important, and sometimes neglected, item in hydrologic equations. Locally, geologic conditions permit inter-basin circulation of ground water. The concept that ground-water basins necessarily terminate at the contact between alluvium and hardrock is not tenable.

Notes: The problem of integrating or coordinating surface water and ground-water use is becoming serious in many areas where the two supplies are hydraulically connected. Because surface waters were generally developed first in the West, later development of connected ground-water supplies has tended to devaluate the prior appropriations on the streams. Legally, those withdrawing such ground water may be in jeopardy. However, the highest beneficial use of the total water resources can only be obtained through a combined or integrated use of both surface and ground water. A simple hypothetical stream-aquifer situation is used to illustrate the influence of ground-water pumping upon surface flows and water available for diversion. One example of a possible solution is presented. Legal and economic factors must also be considered in designing the best physical situation.

Notes: Resistance network analogs (R-analogs) permit solution of ground-water flow systems in media that may be uniform or non-uniform, isotropic or anisotropic, and saturated or unsaturated. Two-dimensional as well as axisymmetric systems can be represented on the analog and complex boundary conditions can easily be simulated. Only steady-state systems can be analyzed with the R-analog. However, systems with moving water tables whereby the rate of movement of the water table is controlled by the flow system below the water table can be solved as a succession of steady states. To capitalize on the special feature of R-analogs, i.e. essentially unlimited opportunity for control of the resistance between any two nodes, use of calibrated variable resistors is desirable. R-analogs are specially adapted to obtain solutions of individual flow systems, of which a vertical cross section is simulated on the analog. In the analog model, resistances are inversely proportional to hydraulic conductivities or transmissibilities, electric current rates are proportional to rates of water flow, and electric potentials are proportional to the sum of pressure head and elevation head. R-analogs may be used to analyze the flow system of a pumped well, a groundwater recharge facility, a series of parallel drains, a seeping dam, a surface stream feeding the ground water, etc. Examples are presented of flow problems involving free-surface development, simultaneous occurrence of saturated and unsaturated parts of the medium, moving water tables, and determination of transmissibility distribution and safe yield of ground-water basins. The application of R-analogs in developing realistic cause-and-effect relationships for use with resistance-capacitance analog models of entire ground-water basins, is discussed and exemplified.

Notes: Numerous articles have been written in the past on the methods and techniques of resistivity and seismic exploration in ground-water studies, however, few articles ever show why a specific type of survey was chosen and what the results or relative costs of such a survey were. In this paper, the authors have attempted to illustrate why particular techniques are chosen and indicate the actual results of the study. In addition, the general cost of the study is mentioned so that one might compare the cost versus other savings or benefits on the project.The four studies indicate that savings on projects may vary from many thousands of dollars to good will depending on the nature of the problem to be solved.

Notes: Describes investigation made to determine cause of excessive corrosion of construction materials of wells supplying domestic water to communities bordering atomic energy plant in South Carolina. Corrosion resulted from natural corrosiveness of soft water with high carbon dioxide and oxygen contents. No effect from atomic energy plant was indicated.

Notes: Water-bearing properties of crystalline rocks are dependent on the occurrence of joints and faults and the extent of weathering. Interstitial openings caused by weathering are mostly at depths of less than 100 feet. Joints are less abundant and openings along joint planes are smaller as depth increases. Openings along fault surfaces also tend to close with depth. These geological observations which indicate a decrease in rock permeability with depth are verified by a study of well yields and water-injection tests. Mean yields per foot of well are 0.23 to 0.30 gpm at 100 feet but only 0.013 to 0.04 gpm at 1000 feet. Mean injection rates per foot of drill hole under 100 psi pressure are 0.11 to 0.4 gpm at 100 feet but only 0.014 to 0.038 gpm at 1000 feet. Median values of both well yields and injection rates are from one-half to one-third of the mean values. Geologic structure is more important than rock type in determining yields and injection rates. The decrease in rock permeability with depth indicates an increase in the unit cost of water with depth. The optimum depth of a well is, therefore, determined largely by economic factors. Unless geologic factors are favorable, wells in crystalline rocks should be less than 600 feet deep. In general, domestic wells should be less than 150 to 250 feet deep.

Notes: This paper is essentially a summary of observations and conclusions of a 3 year hydrologic study (Skinner, 1963) in Prospect Valley, Colorado. A general description of the area is presented, including a brief review of the geology and hydrology with special emphasis on the surface and ground-water supplies for irrigation. The effects of an artificial ground-water recharge operation on ground-water levels and ground-water quality are discussed. Based on historical water deliveries some water resource management aspects are proposed involving conjunctive use of surface and ground-water supplies.

Notes: The great and continued expansion in the utilization of ground water has resulted in an ever increasing need for professional people to enter the field of ground-water resource evaluation and management. Prominent scientists and educators have indicated that the small number of graduates each year is inadequate to meet the current needs much less the future demands for ground-water geologists and engineers. It has been suggested that this deficiency is due in part to the lack of suitable programs of university and college instruction. However, statistical data on the educational and academic research facilities in ground-water geology and hydrology outside the United States and Canada have not been available for study. Statistical data for institutions in the United States and Canada were published in May 1961 (Hackett and Walton, 1961).To obtain data on formal course work and research facilities, the Research Committee of the Technical Division of the National Water Well Association circulated a Questionnaire to appropriate educational institutions outside the United States and Canada in March 1963. This paper is based on completed questionnaires and provides statistical data on university and college activities in the field of ground water. It is hoped that the statistical and descriptive information embodied in this report will provide a suitable background for those who wish to assess the adequacy of available educational and academic research facilities relating to ground-water hydrology and geology.In March, 1963, the Research Committee of the Technical Division of the National Water Well Association mailed a questionnaire on educational facilities in ground-water geology and hydrology to some two hundred foreign institutions of higher learning. By October 1963, some fifty institutions had replied to the questionnaire which was a simplified version adapted from a prototype drafted by James E. Hackett and William C. Walton (1961), and used to make a similar survey on U.S. and Canadian universities. The contents of the questionnaire are given in Table 1.While the response to the questionnaire may seem small at first sight, since only 25 percent of the polled institutions replied, the initiative taken was worthwhile and some interesting conclusions may be drawn from the result. In the first place, the relatively poor participation may be explained, to a large extent, by the fact that a great number of the foreign institu-tions that were questioned do not have a specific interest in ground water. Furthermore, the questionnaires were sent to the schools of engineering or the departments of geology of the institutions, in the hope that there would be an exchange at the local level. This was accomplished in some cases, as may be seen from a summary of the main results in Table 2, but not always. On the other hand, although English is a major international language, it is still not mastered by all foreign scientists and engineers. This may explain why some individuals may have been reluctant in answering to the request for information. We should also realize that the pattern of higher education in some countries is different from ours, which again leads to difficulties in filling out a questionnaire tailored to our needs. It was very rewarding for us to see that France had the largest participation rate (60 percent) of all countries. Probably this is due to the fact that this country apparently emphasizes the subject of hydrogeology more than any other but also, we believe, because we had sent a special French questionnaire to the French institutions. Also, as a result of this policy, the answers were more detailed than those of most of the other participants. It is safe to assume that, if we had written in the native tongue of each country, we would have received more complete answers.Table 2 has been divided somewhat arbitrarily into five classes, according to the strength of the curriculum in subjects related to ground water.Class I: unusually strong programClass II: strong programClass III: significant programClass IV: small programClass V: no programIt is very difficult to draw a well defined boundary between these classes and between some institutions in particular cases, and the five classes have been allotted ten members each for the sake of simplicity. Also, the classification is not the outcome of a contest but a mere indicator of relative interest in the subject of ground water. Several institutions which belong to Classes IV and V have explicitly asked to be informed about the conclusions drawn from this survey, which would tend to prove that they have an interest in the subject but that financial means or other motivation are lacking.A quick glance at Table 2 shows that in Western

Notes: Approximately 4 pounds of refuse per capita per day are produced in the United States. The term refuse, as used here, refers to the useless, unused, unwanted, or discarded solid waste materials resulting from normal community activities; refuse includes such materials as garbage, rubbish, ashes, street refuse, dead animals, and solid industrial wastes (Anon., 1958). Thus, every day our urban population produces over 400,000,000 pounds of refuse that must be disposed of by dumping on land, grinding and disposal with sewage, incineration or that must be made reusable by one or more reclamation processes. Over 1400 communities dispose of their refuse by sanitary landfill techniques, i.e., compaction and covering with compacted earth on suitable land by use of mechanical equipment such as crawler type tractors (Figure 1). Many thousands more dispose of this material in open dumps on land without the degree of sanitary control recommended by health agencies (Figure 2).Wherever refuse is deposited on land, the potential impact on surface waters or subterranean aquifers may be significant. This can be better appreciated when one considers, for example, that ordinary community refuse may have a 5-day BOD of 14,000 to 180,000 ppm and an alkalinity (to MO as CaCO3) of 2600 to more than 23,000 ppm, as shown in Table 1 (Anon., 1952a). In one study bacteriological examination of landfill material showed an average of 740,000 coliforms per gram of refuse. The leachate from a landfill has been found to have a 5-day BOD from 6 to more than 7000 ppm (Carpenter and Setter, 1940; McDermott, 1950).The question is, of course, what does this mean translated into terms of potential ground-water pollution? And further, when this potential is known, what then are the practicalities involved in present disposal practices and their implications with respect to the development of existing and future ground-water pollution problems?

Notes: Abstract Whenever the eye views a spatially-varying gradient of luminance, the Mach bands arise, causing a subjective distribution different from the luminance distribution of the field of view. This phenomenon has been used for the determination of the contrast-transfer function of the visual system when working under normal viewing conditions, i.e., operating in a region where both luminance and detail size are well above threshold. The Mach bands have been measured by making subjective photometric comparisons and the data have been analyzed under the assumption of linearity of response to input. The hypothesis that the visual system may be treated as an approximately linear link in the imaging chain is satisfied best when the luminances are plotted logarithmically. The possibility of this type of investigation is discussed. The result found is compared with apparent subjective contrast measurements of a sine-wave spatial luminance distribution.

Notes: Summary The functional properties of the processing of visual information by the complex eye of Limulus was studied. The spatial distribution of activity that results in the optic nerve when the Limulus eye is exposed to a stationary optical pattern depends upon the transfer characteristics of two subsystems: the dioptric apparatus and the nervous interactions comprising the lateral inhibition system. — The transfer characteristic of the dioptric apparatus is determined by the sensitivity distribution function of single ommatidia. This distribution was measured and found to be approximately of Gauss-function type. The sensitivity falls off to 1/e at a distance of one ommatidium; thus the visual fields of adjacent ommatidia strongly overlap. As a consequence of the overlap, amplitudes of the spatial Fourier components, of which the brightness distribution of the optical surround is made up, are more and more reduced with increasing frequency in the intensity distribution on the receptor mosaic. The amplitude of the spatial frequency 1/λ=0,25 (λ in units of interommatidial distance) is reduced to half of the maximum value, which is attained at zero frequency. It is shown that the amplitude frequency characteristic of the sensitivity distribution function has no zeros, which means that no loss of optical information results from overlap of visual fields. Thus the resolving power of the dioptric apparatus is limited only by the number of receptors per unit area. — The transfer characteristic of the lateral inhibition system in the Limulus eye depends on the distribution of the inhibitory coefficients around the individual receptors. This distribution function was determined from excitatory responses in the optic nerve elicited by a spatial light intensity step function on the receptor mosaic. It is found that this distribution is also Gaussian in form, but decays to 1/e at a distance of eight to nine ommatidia along the major axis of the eye. The average value of the inhibitory coefficients between adjacent ommatidia was found to be 0,025. The amplitude frequency response of the inhibitory system is constant for high spatial frequencies down to 1/λ=0,1 while amplitudes of lower frequency sinusoids are reduced down to nearly half of the maximum value at frequency zero. The amplitude frequency characteristic of the inhibitory system ensures a one to one correspondence between the intensity distribution on the receptor mosaic and the excitation distribution in the optic nerve. The overall transfer characteristic of the eye is derived from the transfer characteristics of the dioptric apparatus and the inhibitory system. This characteristic is of bandpass type with a maximum amplitude response at a frequency of 1/λ=0,07. The overall transfer characteristic was independently confirmed in a separate experiment. The nature of the overall transfer characteristic shows that the inhibitory system does not exactly correct for the overlap of the visual fields of single ommatidia, which in principal the system could do if the distributions of inhibitory coefficients and ommatidia sensitivity were equal. The overall transfer characteristic of the Limulus eye garantees a one to one correspondence between patterns in the optical surround and excitation distributions in the optic nerve. — The average values of the inhibitory coefficients derived from these experiments are at least a factor ten smaller than those determined directly by other investigators. Possible explanations of this discrepency are discussed. — In a separate chapter the overall transfer characteristic for eyes submerged in water is described. It was found that this characteristic does not differ from that determined in air for the eye region which was investigated in the experiments. This result is explained by two properties of the eye which are dependent on the refractive index of the surround medium and whose influences cancel each other: the visual fields of ommatidia are reduced under water, while the divergence angles between the optical axes of adjacent ommatidia also diminish.

Notes: Summary Nonlinear properties of the human pupillary light reflex have been studied using binocular light stimuli of sinusoidally varying intensity. As reported earlier, the pupil responds with a net contraction to the modulation of the light intensity within a wide range of modulation frequencies. Results of the present experiments show that the net contraction does not depend upon the relative phase difference of the binocular light stimuli. However in the lower frequency range, where the in-phase stimuli result in a periodic light reflex, the out-of-phase stimuli fail to do so. These results allow certain conclusions to be drawn regarding the localisation within the photopupil reflex arc of the nonlinearities involved.

Notes: Summary Binary sequences, whose statistical properties follow some law can be predicted with an accuracy depending on their statistical law. The conditional cumulative entropy is a measure of predictability and can be measured in a relatively simple way by using suitable methods. A binary predictor can be realized by the learning matrix for binary signals due to K. Steinbuch. The predictor system depends on the order of the statistical interdependence of the binary digits, which can be expressed in terms of cumulative redundancy. Binary sequences randomly generated by subjects show statistical interdependence between even three preceding digits. Experiments with 121 such binary sequences with 700 digits each have shown that on the average 73% of the digits can be predicted.

Notes: Summary It has been demonstrated that by functional error correction of translator circuits according to the definitions of part 1 a) it is possible to obtain the correct response in spite of a limited number of failing hardware elements; b) failing hardware elements can be located quickly and without large expense c) the cost of this method is insignificantly higher, eventually even lower than conventional diode circuitery (see fig. 14) d) the probability of failure of these circuits is by some magnitudes lower than that of conventional circuits (see fig. 13) e) the number of corrigible circuit failures can be increased under certain conditions (see part 3) likewise by subdivision of the correcting matrix (see table II). In this case the number of hardware elements or the cost of the self-correcting circuits resp. (see fig. 5 and table 2) is reduced further. f) The code redundancy of the non-binary code of the similarity matrix can be fully utilized by multiple discrimination and processing by several correcting matrices (see eq. 12).

Notes: Summary Using the physical and mathematical basis given in two foregoing papers, a differential equation is proposed for a model of the biological 24-hour-periodicity. This oscillation equation contains two characteristic non-linearities describing the self-sustaining property and the “circadian rule”. The right side of the equation (“external force”) represents the controlling environmental conditions, mainly the intensity of illumination. Solutions were obtained for different environmental conditions using a digital computer. Under “constant conditions” the solution of the equation describes oscillations self-sustained within a certain range of environmental conditions. In this range the oscillations fulfil the circadian rule, e.g. for light-active organisms: The frequency and the mean value of the oscillation increase with increasing light intensity; with an additional (arbitrary) threshold separating activity time and rest time for describing an activity rhythm, the α∶ρ (activity time ∶ rest time) ratio and the total amount of activity also increase. Under periodically changing environmental conditions five properties of the “Zeitgeber” used (two distinct intensities with twilight transitions) are variable and varied: The range of oscillation of the Zeitgeber, its frequency, its mean value, its L ∶ D ratio (time relation of light time and dark time), and the duration of the twilights. The most important of the examined properties was the phase angle difference between the (forced) oscillation and the (forcing) Zeitgeber. The general result for light-active organisms was: The phase of the oscillation advances relative to the Zeitgeber (in sofar as the oscillation is synchronized) if the period of the Zeitgeber, or its mean value, or its L∶D ratio, or the duration of the twilights increase. In dark-active organisms, the relation between phase angle difference and the mean value or the L∶D ratio is reversed. Exceptions to this general rule exist in the relation between phase angle difference and L ∶ D ratio if the “free running” period of the oscillation deviates too much from the period of a “weak” Zeitgeber (mainly in dark-active organisms) or if the duration of the twilights is too short (especially if the transitions are rectangular). Single exposures to light (or darkness) during constant conditions result in phase shifts depending in direction and amount on the phase of the oscillation at which the disturbance occured. The resulting response curves depend in range and form on the one hand on the time of measuring the phase shifts (either immediately or after several periods — in the steady state — following the disturbance) and, on the other hand, on the intensity of the initial illumination, on the duration, and on the intensity of the exposures, each in a different manner. Moreover, response curves effective in LD conditions deviate from those measured under constant conditions; the reason being the difference in the energy state of the oscillations in the two conditions. Therefore, it is impossible to derive the phase angle difference between the oscillation and a Zeitgeber in self-sustained oscillations from the measurement of response curves alone. The oscillation equation used contains only one free parameter, the frequency coefficient. If this coefficient is changed, the equation describes other biological rhythms. For instance, with a high value it describes the behaviour of single nerve cells, and that not only in cases of spontaneous rhythmicity (e.g. receptor cells) but also in cases of reactions to single or rhythmic stimuli. Moreover, the derived characteristics of the equation — especially the non-linearities — seem to be significant for other biological problems such as control mechanisms.

Notes: Summary The mean diameter of the human pupil was measured during stimulation of the eye with light of sinusoidally varying intensity and during stationary illumination with the corresponding average intensity. Continuous records of the pupil diameter were obtained using an electronic pupillometer. The light stimuli were electronically controlled by utilizing the Faraday effect and applied under “open loop” conditions. The pupil responded with a net contraction to modulation of the light intensity within a range of modulation frequencies up to 30 c/sec. The net contraction was maximal between 1 and 3 c/sec, but remained significant at high frequencies, which did not result in a periodic light reflex any more. The higher the modulation degree and the average intensity, the larger the net contraction. The dependence of the net contraction upon the modulation frequency is very similar to that of the subjective brightness (Brücke effect), although certain difficulties are encountered in attempting a direct comparison of the two phenomena.

Notes: Summary The optical properties of the compound eye of Drosophila have been analysed using the optomotor reactions of flies with normal and mutant eye pigmentation. The stimulus was provided by cylindrical patterns with different periodic intensity distributions rotating at different speeds. The response consists of a torque about the vertical axis and was recorded under conditions of fixed flight. (Maximum reaction is about 0.04 dyn · cm). The transfer characteristics of the optical system are determined by the inter-ommatidial angle Δϕ, influencing the resolving power and by the width of the visual field of single ommatidia Δρ, influencing the response at high spatial frequencies. The values Δϕ = 4.6° and Δρ= 3.5° are obtained from stimulus-response experiments with Drosophila. They are independent of the presence of screening pigments. Differences in the response of flies with strong (+, se), weak (w a), and missing (w) pigmentation can be explained by the increased amount of scattered light in the pigment-deficient eyes. The overall intensities in the equally illuminated receptors are expected to be in the ratio 1∶1∶8∶25, respectively. The perception of motion depends only on the temporal, not on the spatial phase relations between periodic intensity variations in neighbouring ommatidia. Therefore the inhomogeneous distribution of the inter-ommatidial angle Δϕ changes the resolving power in different parts of the eye without changing the response to motion. Different simultaneous stimuli of equal strength in different parts of the eye are averaged in the perceptive system of Drosophila according to the number of ommatidia in these parts.

Notes: Zusammenfassung/Summary 1. The activity of single nerve cells in the visual system of cats (curarized or encéphale isolé preparations) was investigated. Records were sampled from units in the optic tract, the lateral geniculate body, and the striate cortex. The non-sequential interval distribution and the mean discharge rate of spontaneous activity and of that during stimulation of the retina with continuous light was analysed over long periods. An interval analyser was used. 2. The mean discharge rate of spontaneous activity is highest in the optic tract and decreases significantly towards the visual cortex. The mean values are: 35.5 per sec in the optic tract (13 units), 14.0 per sec in the lateral geniculate (24 units) and 5.7 per sec in the visual cortex (145 units). 3. The variety of possible interval distributions was reduced to 3 characteristic types. As belonging to type I those distributions were classified which showed exponential form. Only the frequency of short intervals was reduced, so that the distribution had a peak at 8–10 msec. The joint interval histogram showed that the successive single discharges were independent from each other. From this it could be assumed that spike generation in these cells occurs according to a Poisson-type process. The initial dead time can be explained by the excitability cycle of the units or by recurrent or collateral synaptic interactions. — Bi- or trimodal interval distributions were labelled as type II. The different peaks were attributed to different activity determining factors. A third group (type III) is found by those distributions which show transitional characteristics between the other two. Only one peak of short intervals is distinguishable and flanked by a wide and unsystematic distribution of longer intervals. 4. In the optic tract mainly type I, in the lateral geniculate mainly type II and in the visual cortex almost always type III distributions were found. 5. The interval distribution from each unit in darkness remained essentially the same under continuous illumination, even though the average discharge rate of optic nerve fibers was considerably changed by stimulation. In cortical cells only little changes of discharge rate were induced by continuous illumination of the retina.

Notes: Summary This paper is concerned with the learning matrix for non-binary signals (LMn) as a classifying network. It can be shown that the properties of a LMn are determined by five parameters. One of these parameters corresponds to a criterion of similarity as the basis of the classification process. Two types of LMn, incorporating different criteria of similarity are investigated and compared as far as the accuracy and the invariance of classification are concerned. The second part of the paper deals with the technical realization of both types of the LMn. There the main problem is the storage of non-binary information in the connecting elements of the LMn. This difficulty can be met by the application of control techniques. Finally some results of investigations on transfluxors are reported which show that transfluxors are suitable connecting elements of a LMn.

Notes: Abstract This article contains data on a metallo-physical study of the structure of uranium subjected to phase recrystallization with various heating and cooling rates. During this heat treatment the uranium may acquire texture, the degree and distribution of which over the sample cross section depends on the parameters of heat treatment (heating conditions, time of holding in high temperature phases, and so forth), as well as on the previous mechanical treatment of the uranium. The degree of texture and even its form can be substantially altered by varying these parameters within certain limits. The greatest degree ofquasi-isotropy is found in samples which during heat treatment come under the influence of stresses created by thermal gradients or external forces and exceeding the yield point of the uranium. The probable mechanism of texture formation in uranium in the process of polymorphic transformations is discussed.

Notes: Abstract The relationship is discussed between the duration of the transitional state of a reactor (from the point of view of reactivity as well as recharging), the specified irradiation stability of the fuel elements, attainable fuel irradiation and the required rate of recharging of the fuel elements for different cycles, In particular, the advantages and disadvantages are compared of equilibrium transition, transition with delayed recharging at a constant rate, transition with constant reactivity and various combinations of these transitions. The conditions are discussed which (in comparison with equilibrium irradiation) permit saving of excess reactivity because of nonoverirradiation of the fuel elements.

Notes: Abstract The specific B-activity of samples of soil, plants, open reservoir water and aerosols was measured for several months prior to startup of the IRT-1000 reactor near Sofia. This survey is presently continuing. On the basis of the measurement results the conclusion was drawn that from the day of startup (September, 1961) until the end of 1962 no radioactive contamination was detected in the vicinity of the reactor in a quantity which exceeded background value.